JP2015184374A - Developing apparatus and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To regulate the height of developer with a simple configuration.SOLUTION: A developing apparatus (Gy) includes: a first conveyance member (16) for conveying developer in a developer container (V); a second conveyance member (17) for conveying the developer in a direction opposite to the first conveyance member (16); an inflow section (8a) arranged outside a downstream end of the second conveyance member (17) in a developer conveyance direction and an end of a developer holding body (R0y), to cause the developer to flow from a second storage chamber (7) toward a first storage chamber (6); a high-speed conveyance section (21) arranged for the inflow section (8a) to convey the developer at a high speed; and a regulation member (23) arranged in a position corresponding to a downstream end of the high-speed conveyance section (21), with respect to a conveyance direction of the first conveyance member (16), to regulate the volume of the developer stored in the first storage chamber (6).

Description

  The present invention relates to a developing device and an image forming apparatus.

  In a conventional image forming apparatus such as a copying machine or a printer, a technique described in Patent Document 1 below is conventionally known as a developing device that develops a latent image into a visible image.

  Japanese Patent Laid-Open No. 2-208675 as Patent Document 1 discloses a developer between a first transfer device (5) for supplying a developer to a developing roller (2) and a first transfer device (5). And a second transfer device (6) that conveys the toner while circulating it. In the developing device described in Patent Document 1, when the height regulating plate (31) is supported on the side surface of the first transfer device (5) and the height of the developer exceeds the height regulating plate (31), the height is increased. A technique is described in which the height of the developer in the first transfer device (5) is kept constant by overflowing the developer from the regulation plate (31) and dropping into the developer tank (12).

JP-A-2-208675 (4th page, lower right column, last line to 5th page, lower left column, 4th line, FIG. 3)

  An object of the present invention is to regulate the height of a developer with a simple configuration.

In order to solve the technical problem, the developing device of the invention according to claim 1 comprises:
A developer container containing a developer;
A developer holder disposed in the developer container, holding and rotating the developer on the surface, and facing the image carrier on which the latent image is formed;
A first conveyance member having a rotation shaft and a conveyance blade supported by the rotation shaft, and conveying the developer in the developer container while stirring;
A rotating shaft and a transport blade supported by the rotating shaft, and disposed in parallel with the first transport member in a horizontal direction, wherein the developer is in a direction opposite to the first transport member. A second conveying member that conveys while stirring,
The space between the first transport member and the second transport member, the space inside the developing container, the first storage chamber in which the first transport member is disposed, and the second A partition member that partitions into a second storage chamber in which the transport member is disposed;
Developed from the second storage chamber toward the first storage chamber, provided at the downstream end of the second transport member in the developer transport direction and outside the end of the developer holder. An inflow part into which the agent flows,
A high-speed conveyance unit that is provided corresponding to the inflow portion with respect to the conveyance direction of the first conveyance member and conveys the developer at a higher speed than the region corresponding to the developer holding body,
A regulating member that is provided at a position corresponding to the downstream end of the high-speed conveyance unit with respect to the conveyance direction of the first conveyance member and regulates the volume of the developer accommodated in the first accommodation chamber;
It is provided with.

The invention according to claim 2 is the developing device according to claim 1,
The high-speed transport unit in which the rotation shaft is formed thinner than the thickness of the rotation shaft of the first transport member in the region corresponding to the developer holder,
It is provided with.

The invention described in claim 3 is the developing device according to claim 1 or 2,
The high-speed transport unit having an outer diameter formed larger than an outer diameter of a transport blade of the first transport member in a region corresponding to the developer holder;
It is provided with.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects,
The high-speed conveyance in which the distance traveled in the axial direction is longer than the distance traveled by the spiral transport blade in the axial direction when the first transport member rotates once in the region corresponding to the developer holder. Part,
It is provided with.

In order to solve the technical problem, an image forming apparatus according to claim 5 is provided.
An image carrier,
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
The developing device according to any one of claims 1 to 4, which develops a latent image on the surface of the image carrier into a visible image;
A transfer device for transferring a visible image of the surface of the image carrier to a medium;
A fixing device for fixing a visible image on the surface of the medium;
It is provided with.

According to the first and fifth aspects of the present invention, the height of the developer can be regulated with a simple configuration as compared with the case where the configuration of the present invention is not provided.
According to the second to fourth aspects of the present invention, the developer that has flowed in from the inflow portion can be quickly conveyed downstream.

FIG. 1 is an explanatory diagram of the image forming apparatus according to the first embodiment. FIG. 2 is an explanatory diagram of a main part of the image forming apparatus according to the first embodiment. FIG. 3 is an explanatory diagram of the developing device according to the first embodiment. 4 is a cross-sectional view taken along line IV-IV in FIG. 5 is a cross-sectional view taken along line VV in FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is an explanatory diagram of the regulating member of the second embodiment, and corresponds to FIG. 5 of the first embodiment. FIG. 8 is an explanatory diagram of the regulating member of the third embodiment and corresponds to FIG. 5 of the first embodiment. FIG. 9 is an explanatory diagram of the regulating member of the fourth embodiment, and corresponds to FIG. 5 of the first embodiment.

Next, examples as specific examples of embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

FIG. 1 is an explanatory diagram of the image forming apparatus according to the first embodiment.
FIG. 2 is an explanatory diagram of a main part of the image forming apparatus according to the first embodiment.
In FIG. 1, a copier U as an example of an image forming apparatus according to a first exemplary embodiment of the present invention is an example of a recording unit, and includes a printer unit U1 as an example of an image recording apparatus. A scanner unit U2 as an example of a reading unit and an example of an image reading device is supported on the upper portion of the printer unit U1. An auto feeder U3 as an example of a document transport device is supported on the upper portion of the scanner unit U2. The scanner unit U2 of the first embodiment supports a user interface UI as an example of an input unit. The user interface UI can be operated by the operator by inputting the user interface UI.

  A document tray TG1 as an example of a medium container is disposed on the upper part of the auto feeder U3. A plurality of documents Gi to be copied can be stacked and stored in the document tray TG1. A document discharge tray TG2 as an example of a document discharge unit is formed below the document tray TG1. A document transport roll U3b is disposed between the document tray TG1 and the document discharge tray TG2 along the document transport path U3a.

A platen glass PG as an example of a transparent document table is disposed on the upper surface of the scanner unit U2. In the scanner unit U2 of the first embodiment, a reading optical system A is disposed below the platen glass PG. The optical system A for reading in Example 1 is supported so as to be movable in the left-right direction along the lower surface of the platen glass PG. The reading optical system A is normally stopped at the initial position shown in FIG.
On the left side of the optical system A for reading, an imaging element CCD as an example of an imaging member is disposed. An image processing unit GS is electrically connected to the image sensor CCD.
The image processing unit GS is electrically connected to the writing circuit DL of the printer unit U1. The writing circuit DL is electrically connected to LED heads LHy, LHm, LHc, and LHk as an example of a latent image forming apparatus.

Above each of the LED heads LHy to LHk, photosensitive drums PRy, PRm, PRc, and PRk as an example of an image holding member are disposed.
Charging rolls CRy, CRm, CRc, CRk as an example of a charger are arranged to face each of the photosensitive drums PRy to PRk. A charging voltage is applied from the power supply circuit E to the charging rolls CRy to CRk. The power supply circuit E is controlled by a controller C as an example of a control unit. The controller C performs various controls by transmitting and receiving signals to and from the image processing unit GS and the writing circuit DL.
In the writing areas Q1y, Q1m, Q1c, Q1k set on the downstream side of the charging rolls CRy to CRk with respect to the rotation direction of the photosensitive drums PRy to PRk, LEDs are formed with respect to the surfaces of the photosensitive drums PRy to PRk. Write light is emitted from the heads LHy to LHk.
The developing devices Gy, Gm, Gc, and Gk are provided in the developing areas Q2y, Q2m, Q2c, and Q2k set downstream of the writing areas Q1y to Q1k with respect to the rotation direction of the photosensitive drums PRy to PRk. The drums PRy to PRk are arranged to face the surface.

Primary transfer areas Q3y, Q3m, Q3c, and Q3k are set on the downstream side of the development areas Q2y to Q2k with respect to the rotation direction of the photosensitive drums PRy to PRk. In the primary transfer regions Q3y to Q3k, they are in contact with an intermediate transfer belt B as an example of an intermediate transfer member. In the primary transfer areas Q3y, Q3m, Q3c, and Q3k, primary transfer rolls T1y, T1m as an example of a primary transfer unit are disposed on the opposite side of the photosensitive drums PRy to PRk across the intermediate transfer belt B. T1c and T1k are arranged.
Drum cleaners CLy, CLm, CLc, and CLk as an example of an image carrier cleaner are disposed downstream of the primary transfer regions Q3y to Q3k with respect to the rotation direction of the photosensitive drums PRy to PRk. .

  A belt module BM as an example of an intermediate transfer device is disposed above the photosensitive drums PRy to PRk. The belt module BM includes the intermediate transfer belt B. The intermediate transfer belt B includes a driving roll Rd as an example of a driving member, a tension roll Rt as an example of a stretching member, a walking roll Rw as an example of a meandering correction member, and an idler roll Rf as an example of a driven member. It is rotatably supported by a backup roll T2a as an example of a counter member in the secondary transfer region and primary transfer rolls T1y, T1m, T1c, T1k.

On the opposite side of the backup roll T2a across the intermediate transfer belt B, a secondary transfer roll T2b as an example of a secondary transfer member is disposed. The backup roll T2a and the secondary transfer roll T2b constitute a secondary transfer device T2. A secondary transfer region Q4 is formed by a region where the secondary transfer roll T2b and the intermediate transfer belt B face each other.
The primary transfer rolls T1y to T1k, the intermediate transfer belt B, the secondary transfer unit T2, and the like constitute a transfer device T1 + T2 + B of Example 1 that transfers an image formed on the photosensitive drums PRy to PRk to a medium. .

A belt cleaner CLb, which is an example of an intermediate transfer member cleaner, is disposed downstream of the secondary transfer region Q4 with respect to the rotation direction of the intermediate transfer belt B.
Above the belt module BM, cartridges Ky, Km, Kc, and Kk as an example of a developer container are disposed. Each of the cartridges Ky to Kk contains a developer to be supplied to the developing devices Gy to Gk. The cartridges Ky to Kk and the developing devices Gy to Gk are connected by a developer replenishing device (not shown).

In the lower part of the printer unit U1, paper feed trays TR1 to TR3 are arranged as an example of a medium container. The paper feed trays TR1 to TR3 are detachably supported in the front-rear direction by a guide rail GR as an example of a guide member. Sheets T as an example of a medium are accommodated in the sheet feed trays TR1 to TR3.
A pickup roll Rp as an example of a medium take-out member is disposed on the upper left side of the paper feed trays TR1 to TR3. On the left side of the pick-up roll Rp, a separating roll Rs as an example of a separating member is disposed.
On the left side of each of the paper feed trays TR1 to TR3, a medium conveyance path SH extending upward is formed. A plurality of transport rolls Ra as an example of a medium transport member are arranged in the transport path SH. In the transport path SH, a registration roll Rr as an example of a feeding member is disposed on the downstream side in the transport direction of the sheet S and on the upstream side of the secondary transfer region Q4.

A fixing device F is disposed above the secondary transfer region Q4. The fixing device F includes a heating roll Fh as an example of a heating member and a pressure roll Fp as an example of a pressure member. A fixing region Q5 is configured by a contact region between the heating roll Fh and the pressure roll Fp.
A discharge roller Rh as an example of a medium conveying member is disposed obliquely above the fixing device F. A discharge tray TRh as an example of a medium discharge portion is formed on the right side of the discharge roller Rh.

(Description of image forming operation)
The plurality of documents Gi stored in the document tray TG1 sequentially passes through the document reading position on the platen glass PG and is discharged to the document discharge tray TG2.
When the automatic feeder U3 is used to automatically convey and copy a document, each document that sequentially passes through the reading position on the platen glass PG with the reading optical system A stopped at the initial position. Gi is exposed.
When the operator places the document Gi on the platen glass PG by hand, the optical system A for reading moves in the left-right direction, and the document on the platen glass PG is scanned while being exposed.

The reflected light from the document Gi passes through the optical system A and is collected on the image sensor CCD. In the imaging device CCD, the reflected light of the original collected on the imaging surface is converted into electrical signals of red: R, green: G, blue: B.
The image processing unit GS converts RGB electrical signals input from the image sensor CCD into black: K, yellow: Y, magenta: M, cyan: C image information and temporarily stores them. The image processing unit GS outputs the temporarily stored image information to the writing circuit DL as image information for forming a latent image at a preset time.
When the original image is a single color image, so-called monochrome, image information of only black: K is input to the writing circuit DL.

The writing circuit DL has driving circuits for respective colors Y, M, C, and K (not shown), and an LED head arranged for each color at a preset time with a signal corresponding to input image information. Output to LHy to LHk.
The surface of each photoconductor drum PRy to PRk is charged by charging rolls CRy to CRk. The LED heads LHy to LHk form electrostatic latent images on the surfaces of the photosensitive drums PRy to PRk in the writing areas Q1y to Q1k. The developing devices Gy to Gk develop the electrostatic latent images on the surfaces of the photosensitive drums PRy to PRk into toner images as an example of visible images in the development areas Q2y to Q2k. When the developer is consumed in the developing devices Gy to Gk, the developers are supplied from the cartridges Ky to Kk to the developing devices Gy to Gk according to the consumption amount.

  The toner images on the surfaces of the photosensitive drums PRy to PRk are conveyed to the primary transfer areas Q3y, Q3m, Q3c, and Q3k. A primary transfer voltage having a polarity opposite to the charging polarity of the toner is applied to each of the primary transfer rolls T1y to T1k from a power supply circuit E at a preset time. Therefore, in the primary transfer areas Q3y to Q3k, the toner images on the photosensitive drums PRy to PRk are sequentially transferred to the intermediate transfer belt B by the primary transfer voltage. In the case of a K-color single-color image, only the K-color toner image is transferred from the K photosensitive drum PRk to the intermediate transfer belt B.

  The toner images on the photosensitive drums PRy to PRk are primarily transferred to an intermediate transfer belt B as an example of an intermediate transfer member by the primary transfer units T1y, T1m, T1c, and T1k. Residues and deposits on the surface of the photoconductor drums PRy to PRk after the primary transfer are cleaned by the photoconductor cleaners CLy to CLk. The cleaned surfaces of the photosensitive drums PRy to PRk are recharged by charging rolls CRy to CRk.

The sheets S in the respective sheet feeding trays TR1 to TR3 are taken out by the pickup roll Rp at a preset sheet feeding timing. The sheets S picked up by the pick-up roll Rp are separated one by one by the rolling roll Rs when picked up in a state where a plurality of sheets S are overlapped. The sheet S that has passed the separating roll Rs is conveyed to the registration roll Rr by a plurality of conveying rolls Ra.
The registration roll Rr sends out the sheet S in accordance with the timing when the toner image on the surface of the intermediate transfer belt B moves to the secondary transfer region Q4.

The toner image on the surface of the intermediate transfer belt B is transferred to the sheet S fed from the registration roll Rr by the secondary transfer voltage applied to the secondary transfer roll T2b when passing through the secondary transfer area Q4. .
The surface of the intermediate transfer belt B after passing through the secondary transfer region Q4 is cleaned by removing residual toner by the belt cleaner CLb.
When the sheet S that has passed through the secondary transfer area Q4 passes through the fixing area Q5, the toner image is heated and pressed by the fixing device F to be fixed.
The recording sheet S on which the toner image is fixed is discharged to the paper discharge tray TRh by the discharge roller Rh.

(Description of developing device)
FIG. 3 is an explanatory diagram of the developing device according to the first embodiment.
4 is a cross-sectional view taken along line IV-IV in FIG.
Next, the developing devices Gy, Gm, Gc, and Gk according to the first embodiment of the present invention will be described. Since the developing devices Gy, Gm, Gc, and Gk of the respective colors are configured in the same manner, the development of the Y color is performed. Only the apparatus Gy will be described in detail, and detailed descriptions of the other color developing apparatuses Gm, Gc, Gk will be omitted.
3 and 4, the developing device Gy disposed to face the photosensitive drum PRy has a developing container V that stores a two-component developer containing toner and a carrier. In FIG. 3, the developing container V has a lower container body 1. A container cover 2 as an example of a lid member is supported on the upper part of the container body 1. The container cover 2 closes the upper surface of the container body 1.

3 and 4, the developing container main body 1 is formed with a developing roll chamber 4 as an example of an accommodating portion of a developer holding body in the upper left part of the inside. A supply chamber 6 as an example of a first storage chamber is formed below the developing roll chamber 4. The supply chamber 6 is connected to the developing roll chamber 4. On the right side of the supply chamber 6, a stirring chamber 7 as an example of a second storage chamber is formed.
The supply chamber 6 and the stirring chamber 7 are partitioned by a partition wall 8 as an example of a partition member. In FIG. 4, a first inflow portion 8 a that connects the supply chamber 6 and the stirring chamber 7 is formed in front of the partition wall 8 as an example of a first connection portion. In the first embodiment, the first inflow portion 8 a is disposed in front of the front end of the developing roll chamber 4. In addition, a second inflow portion 8 b that connects the supply chamber 6 and the stirring chamber 7 is formed behind the partition wall 8 as an example of a second connection portion.

  The developing roll chamber 4 accommodates a developing roll R0y as an example of a developer holding body. The developing roll R0y has a part of the upper left outer surface facing the photosensitive drum PRy. The developing roll R0y has a magnet roll 11 as an example of a magnet member. In FIG. 4, the magnet roll 11 is supported by the developing container V so as not to rotate. 3 and 4, a developing sleeve 12 as an example of a rotating body is disposed on the outer periphery of the magnet roll 11. The developing sleeve 12 is rotatably supported by the developing container V. A gear G0 as an example of a drive transmission member is supported at the rear end of the developing sleeve 12. The gear G0 is configured to be able to transmit drive from a motor (not shown) as an example of a drive source. In the developing device Gy of Example 1, when the drive is transmitted from the motor, the developing sleeve 12 rotates in the same direction as the movement direction of the surface of the photosensitive drum PRy in the developing region Q2y.

Below the developing roll chamber 4, a trimmer 13 as an example of a regulating member having a layer thickness is disposed. The trimmer 13 of Example 1 is formed in a columnar shape extending in the front-rear direction. The trimmer 13 is supported with respect to the developing sleeve 12 in a non-rotatable state with a predetermined gap.
The magnet roll 11 is provided with a developing magnetic pole S1 corresponding to the developing region Q2y. Further, a trimming magnetic pole N2 as an example of a magnetic pole for regulating the layer thickness is provided at a position facing the trimmer 13. The trimming magnetic pole N2 is composed of a magnetic pole having a polarity opposite to that of the developing magnetic pole S1. A transport magnetic pole N1 having a polarity opposite to that of the developing magnetic pole S1 is provided on the downstream side of the developing magnetic pole S1 with respect to the rotation direction of the developing sleeve 12. A pick-off magnetic pole S2 as an example of a magnetic pole for detachment of the developer is provided on the downstream side of the conveying magnetic pole N1 with respect to the rotation direction of the developing sleeve 12. The pick-off magnetic pole S2 is composed of a magnetic pole having a polarity opposite to that of the carrier magnetic pole N1. A pickup magnetic pole S3 as an example of a magnetic pole for attracting the developer is provided on the downstream side of the pick-off magnetic pole S2 and the upstream side of the trimming magnetic pole N2 with respect to the rotation direction of the developing sleeve 12. The pickup magnetic pole S3 is composed of a magnetic pole having the same polarity as that of the pick-off magnetic pole S2 and having a polarity opposite to that of the trimming magnetic pole N2.

3 and 4, a supply auger 16 as an example of a first conveying member is disposed in the supply chamber 6. The supply auger 16 has a rotating shaft 16a extending in the front-rear direction. A spiral conveying blade 16b is supported on the outer periphery of the rotating shaft 16a. A gear G1 as an example of a drive transmission member is supported at the rear end of the rotating shaft 16a.
In the stirring chamber 7, a stirring auger 17 as an example of a second transport member is disposed. As with the supply auger 16, the stirring auger 17 includes a rotating shaft 17a, a conveying blade 17b, and a gear G2. The gears G0 to G2 mesh with each other.
In FIG. 4, a supply port 7 a for supplying developer from the cartridge Ky is formed at the rear of the stirring chamber 7.

(Developer function)
In the developing devices Gy to Gk having the above-described configuration, when image formation is started, the motor is driven to rotate the augers 16 and 17 and the developing rolls R0y to R0k. In the first embodiment, when the supply auger 16 rotates, the supply auger 16 conveys the developer in the supply chamber 6 while stirring the developer from the first inflow portion 8a toward the second inflow portion 8b as indicated by an arrow Ya. To do. The developer conveyed to the second inflow portion 8b flows into the stirring chamber 7 through the second inflow portion 8b. When the stirring auger 17 rotates, the stirring auger 17 conveys the developer in the stirring chamber 7 while stirring from the second inflow portion 8b toward the first inflow portion 8a as indicated by an arrow Yb. The developer conveyed to the first inflow portion 8a flows into the supply chamber 6 through the first inflow portion 8a. Therefore, the supply chamber 6 and the stirring chamber 7 constitute a circulation chamber 6 + 7.

  The developer in the supply chamber 6 is attracted to the developing sleeve 12 by the magnetic force of the pickup magnetic pole S3. When the developer adsorbed on the developing sleeve 12 passes through the trimmer 13, only a preset developer corresponding to the gap between the trimmer 13 and the developing sleeve 12 passes. The developer that has passed through the trimmer 13 develops the latent images on the photosensitive drums PRy to PRk in the development areas Q2y to Q2k. The developer that has not been used for development is conveyed while adsorbed on the surface of the developing sleeve 12 by a magnetic field between the developing magnetic pole S1 and the conveying magnetic pole N1, a magnetic field between the conveying magnetic pole N1 and the pick-off magnetic pole S2, or the like. . Between the pick-off magnetic pole S2 and the pick-up magnetic pole S3 having the same polarity, the magnetic force that attracts the developer to the developing sleeve 12 decreases. Therefore, the developer adsorbed on the surface of the developing sleeve 12 is separated from the developing sleeve 12 between the pick-off magnetic pole S2 and the pick-up magnetic pole S3 and returned to the circulation chamber 6 + 7.

5 is a cross-sectional view taken along line VV in FIG.
4 and 5, the rotating shaft 16a of the supply auger 16 according to the first embodiment has a small-diameter portion 21 as an example of a high-speed transport unit at the upstream end in the developer transport direction. The small-diameter portion 21 includes a first inflow portion 8a as an example of an inflow portion, and is located downstream of the first inflow portion 8a in the developer transport direction and in an axial region where development is performed by the developing roll R0y. It is formed in a range upstream of the upstream end 22 a of a certain developing width 22. The small-diameter portion 21 is formed to have a smaller diameter than the thickness of the rotating shaft 16 a corresponding to the developing width 22. In addition, the outer diameter of the conveyance blade 16b is set to be the same over the entire region in the front-rear direction. Therefore, in the small diameter portion 21, the cross-sectional area where the developer is sent by the conveying blade 16 b is larger than the region corresponding to the development width 22. Therefore, in the small diameter portion 21, the developer transport speed is higher than that in the region corresponding to the development width 22. That is, the developer that has flowed into the supply chamber 6 from the first inflow portion 8a is quickly conveyed downstream.

6 is a sectional view taken along line VI-VI in FIG.
5 and 6, in the supply chamber 6 according to the first embodiment, a restriction protrusion 23 as an example of a restriction member is provided at a position downstream of the small diameter portion 21 and upstream of the upstream end 22 a of the developing width 22. Has been placed. As shown in FIG. 6, the lower end of the regulation protrusion 23 of the first embodiment is formed in a shape along the outer periphery of the supply auger 16 on the side closer to the pickup magnetic pole S <b> 3 with respect to the outer periphery of the supply auger 16.

  In the developing device Gy of Example 1 having the above-described configuration, the developer corresponding to the developing ability is adsorbed in the developing width 22 where the development is performed, based on the charging characteristics of the developer, the magnetic flux density of the pickup magnetic pole S3, and the like. . In recent years, the developing device Gy has been downsized and the driving torque of the developing roll R0y has been reduced. If the magnetic flux density remains large in a small developing device, the magnetic force reaches far, for example, the developer in the stirring chamber may be affected by the magnetic force. In addition, when the torque is low, if a large amount of developer is adsorbed to the developing roll R0y with a strong magnetic force, the total weight of the developing roll R0y and the developer becomes heavy, and the developing roll R0y rotates poorly and uneven rotation occurs. There is a fear. Therefore, it is common to reduce the magnetic flux density of the pickup magnetic pole S3 and the like in accordance with the downsizing and the reduction in torque of the developing device.

When the magnetic flux density of the pickup magnetic pole S3 is lowered, it is advantageous to bring the developer as close as possible to the surface of the developing roll R0y in order to stably attract the developer. As a method of bringing the developer closer to the developing roll R0y, it is conceivable to increase the shaft diameter of the rotating shaft 16a of the supply roll 16.
However, when the shaft diameter of the rotating shaft 16a is increased, the developer transport speed is decreased. Here, if the shaft diameter of the first inflow portion 8a is large, the developer that has flowed into the supply chamber 6 through the first inflow portion 8a is likely to stay in the first inflow portion 8a. When the developer stays, there is a possibility that the developer with insufficient stirring is supplied to the developing roll R0y. On the other hand, in Example 1, the small diameter part 21 is formed corresponding to the 1st inflow part 8a. Therefore, the developer that has flowed in from the first inflow portion 8a is quickly conveyed downstream. Therefore, the stay of the developer and the occurrence of insufficient stirring are suppressed.

  However, in this configuration, a difference occurs in the developer conveyance speed at the position of the downstream end of the small diameter portion 21. Therefore, at the position of the downstream end of the small diameter portion 21, as shown by the one-dot chain line in FIG. If the developer volume increases, the development width 22 may become too high. When the bulk of the developer becomes too high, the developer picked off from the developing roll R0y may fall onto the bulky developer and be immediately adsorbed to the developing roll R0y without being sufficiently stirred. . When a developer that is not sufficiently stirred is used for development, there is a possibility of causing a decrease in image quality such as a decrease in density or white spots. In particular, in a small-sized developing device, the distance between the developing roll R0y and the supply auger 16 is getting closer, and the influence is likely to be remarkable.

On the other hand, in the developing device Gy of the first embodiment, the restriction projection 23 is disposed at a position corresponding to the downstream end of the small diameter portion 21. Therefore, in the developing width 22 on the downstream side of the restricting protrusion 23, the volume of the developer is restricted to an amount set by the restricting protrusion 23 as shown by a one-dot chain line in FIG. Therefore, in the development width 22, it is suppressed that the bulk of the developer becomes too high. Therefore, it is possible to suppress a decrease in image quality. Further, unlike the configuration described in Patent Document 1, the regulation protrusion 23 of Example 1 does not require a configuration for collecting the overflowing developer, and can regulate the bulk with a simple and low-cost configuration. is there.
Further, as shown in FIG. 6, the restricting protrusion 23 of the first embodiment is formed up to the pickup magnetic pole S3 side. Therefore, it is possible to suppress the bulk from being excessively increased by the developer that is limited by the trimmer 13 and returns to the supply chamber 6.

FIG. 7 is an explanatory diagram of the regulating member of the second embodiment, and corresponds to FIG. 5 of the first embodiment.
Next, a second embodiment of the present invention will be described. In the description of the second embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 7, in the developing device Gy of the second embodiment, unlike the first embodiment, the rotation shaft 16a is formed identically in the front-rear direction. In the second embodiment, the part of the conveying blade 31 corresponding to the first inflow portion 8 a is formed to have a larger diameter than the outer diameter of the part of the conveying blade 16 b corresponding to the developing width 22. That is, the large-diameter conveying blade 31 constitutes the high-speed conveying unit of the second embodiment.

(Operation of Example 2)
In the developing device Gy according to the second embodiment having the above-described configuration, as in the first embodiment, the developer flowing in from the first inflow portion 8a can be quickly conveyed downstream. Further, the developing device Gy of the second embodiment has the same function and effect as the first embodiment.

FIG. 8 is an explanatory diagram of the regulating member of the third embodiment and corresponds to FIG. 5 of the first embodiment.
Next, a third embodiment of the present invention will be described. In the description of the third embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description thereof will be omitted. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 8, in the developing device Gy of the third embodiment, unlike the first embodiment, the rotation shaft 16a is formed identically in the front-rear direction. Further, in the third embodiment, the conveyance blade 41 corresponding to the first inflow portion 8a has a development distance, that is, a so-called pitch, in which the spiral conveyance blade 41 advances in the axial direction when the rotation shaft 16a rotates once. The pitch of the portion corresponding to the width 22 is also formed large. That is, the high-speed conveyance part of Example 3 is comprised by the conveyance blade | wing 41 with this large pitch.

(Operation of Example 3)
In the developing device Gy according to the third embodiment having the above-described configuration, the developer that has flowed in from the first inflow portion 8a can be quickly conveyed downstream as in the first and second embodiments. Further, the developing device Gy of the third embodiment has the same function and effect as the first embodiment.

FIG. 9 is an explanatory diagram of the regulating member of the fourth embodiment, and corresponds to FIG. 5 of the first embodiment.
Next, a description will be given of a fourth embodiment of the present invention. In the description of the fourth embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. To do.
This embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 9, the developing device Gy according to the fourth exemplary embodiment includes a ceiling portion 51 as an example of a restriction portion instead of the restriction protrusion 23. The ceiling portion 51 of the fourth embodiment is formed so that the height of the ceiling portion of the container cover 2 is lower than the portion corresponding to the developing width 22 in the range corresponding to the small diameter portion 21.

(Operation of Example 4)
In the developing device Gy of Example 4 having the above-described configuration, the bulk of the developer in the developing width 22 can be regulated by the ceiling 51 as in the case of the regulating protrusion 23 of Example 1. Therefore, the developing device Gy of the fourth embodiment has the same function and effect as the first embodiment.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H04) of the present invention are exemplified below.
(H01) Although the copying machine as an example of the image forming apparatus has been illustrated in the above embodiment, the present invention is not limited to this. For example, the copying machine is configured by a printer, a FAX, or a multifunction machine having a plurality or all of these functions. It is also possible.
(H02) In the above embodiment, the copying machine U has exemplified the configuration in which four color developers are used. However, the present invention is not limited to this. For example, a single color image forming apparatus, five or more colors, or three colors or less. The present invention can also be applied to a multicolor image forming apparatus.

(H03) In the above-described embodiment, the configurations of Embodiments 1 to 3 are exemplified as the high-speed transport unit, but the present invention is not limited to this. For example, the configurations of the first to third embodiments can be combined.
(H04) In the above embodiment, the shape and size of the restricting member and the length in the front-rear direction are not limited to the configurations illustrated in the embodiment, and can be arbitrarily changed according to the design, specifications, and the like.

6 ... first containment chamber,
7 ... second accommodation room,
8 ... partitioning member,
8a ... inflow part,
16 ... 1st conveyance member,
16a, 17a ... rotating shaft,
16b, 17b ... conveying blades,
17 ... second conveying member,
21, 31, 41 ... high-speed conveyance unit,
23, 51 ... restricting member,
F: Fixing device,
Gy, Gm, Gc, Gk ... developing device,
LHy, LHm, LHc, LHk ... latent image forming device,
PRy, PRm, PRc, PRk ... Image carrier,
R0y, R0m, R0c, R0k ... developer holder,
S ... medium
T1 + T2 + B ... transfer device,
U: Image forming apparatus,
V: Developer container.

Claims (5)

A developer container containing a developer;
A developer holder disposed in the developer container, holding and rotating the developer on the surface, and facing the image carrier on which the latent image is formed;
A first conveyance member having a rotation shaft and a conveyance blade supported by the rotation shaft, and conveying the developer in the developer container while stirring;
A rotating shaft and a transport blade supported by the rotating shaft, and disposed in parallel with the first transport member in a horizontal direction, wherein the developer is in a direction opposite to the first transport member. A second conveying member that conveys while stirring,
The space between the first transport member and the second transport member, the space inside the developing container, the first storage chamber in which the first transport member is disposed, and the second A partition member that partitions into a second storage chamber in which the transport member is disposed;
Developed from the second storage chamber toward the first storage chamber, provided at the downstream end of the second transport member in the developer transport direction and outside the end of the developer holder. An inflow part into which the agent flows,
A high-speed conveyance unit that is provided corresponding to the inflow portion with respect to the conveyance direction of the first conveyance member and conveys the developer at a higher speed than the region corresponding to the developer holding body,
A regulating member that is provided at a position corresponding to the downstream end of the high-speed conveyance unit with respect to the conveyance direction of the first conveyance member and regulates the volume of the developer accommodated in the first accommodation chamber;
A developing device comprising: The high-speed transport unit in which the rotation shaft is formed thinner than the thickness of the rotation shaft of the first transport member in the region corresponding to the developer holder,
The developing device according to claim 1, further comprising: The high-speed transport unit having an outer diameter formed larger than an outer diameter of a transport blade of the first transport member in a region corresponding to the developer holder;
The developing device according to claim 1, further comprising: The high-speed conveyance in which the distance traveled in the axial direction is longer than the distance traveled by the spiral transport blade in the axial direction when the first transport member rotates once in the region corresponding to the developer holder. Part,
The developing device according to claim 1, further comprising: An image carrier,
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
The developing device according to any one of claims 1 to 4, which develops a latent image on the surface of the image carrier into a visible image;
A transfer device for transferring a visible image of the surface of the image carrier to a medium;
A fixing device for fixing a visible image on the surface of the medium;
An image forming apparatus comprising:

Images